Free Shipping On Orders Over $49. Details

Talk to a Mustang Expert
M-F 8:30A-11P, Sat-Sun 8:30A-9P
Win $5,000 From Rovos! Enter daily!

Flowmaster American Thunder Axle-Back Exhaust (15-19 EcoBoost w/o Active Exhaust)

Market Price $728.99 You Save 12% ($85.04)
Our Price


FREE Shipping

  • Item 384451A

Will this fit your Vehicle?

In Stock Ships same business day.
Ship to: Ashburn - 20149
Sorry, please enter a valid US or CA postal code
We're sorry, zip can't be updated at this time.
    Create a list
    Add to New List

    Saved - View your saved items

    We're sorry. We couldn't save this product at this time.

    Features, Video & Details

    • Aggressive Flowmaster Sound
    • Durable 409 Stainless Steel Construction
    • Mandrel-Bent Tubing
    • Polished 304 Stainless Steel 4" Tips
    • Includes a pair of Flowmaster Super 10 Series Mufflers
    • Not Compatible with Active Exhaust
    • Fits All 2015-2019 EcoBoost Mustangs

    Review & Installation Video

    Review & Install Video

    Signature Flowmaster Sound. Add the unmistakable Flowmaster sound to your S550 EcoBoost Mustang with an American Thunder Series Axle-Back Exhaust system from AmericanMuscle. The Flowmaster American Thunder Axle-Back Exhaust with its mandrel-bent tubing will greatly improve your Mustang's exhaust flow for an increase in power, and the included baffled mufflers will improve your exhausts sound for an aggressive muscle car exhaust note.

    Stainless Steel Construction. Constructed from durable 16 gauge 409 stainless steel tubing for its corrosion resistant properties, the Flowmaster American Thunder Axle-Back features Super 10 Series mufflers with massive 4.0" diameter polished stainless steel tips for impressive muscle car looks and sound. As an added bonus, the tips are embossed with the "Flowmaster" logo for true custom styling.

    Cut & Clamp Installation. The installation of this Axle-Back Exhaust requires cutting and removing the stock muffler assemblies and clamping the new muffler assemblies in place. Clamps and instructions are provided.

    Application. This Flowmaster American Thunder Axle-Back Exhaust system is designed to fit the 2015-2019 EcoBoost Mustangs without the Active Valve Exhaust.

    Fitment: 2015 2016 2017 2018 2019 Details

    MPN# 817748

    CA Residents: WARNING: Cancer and Reproductive Harm -

    What's in the Box
    • (1) Left Muffler Assembly
    • (1) Right Muffler Assembly
    • (2) 2-1/4" Clamps
    Installation Info
    Tech Specs
    Axle-Back Exhaust Specifications
    Piping Material: 409 Stainless Steel Tip Material : Polished 304 Stainless Steel
    Piping Size:  3.0" Tip Size: 4.0"
    Muffler Type: Baffled Fitment: 2015-2017 EcoBoost
    Will it fit my Mustang?

    You Might Also Like

    Customer Photos (1) Submit Your Photo

    View 1 Photo

    More Products You Might Like

    Questions & Answers (6)

    5 Top Rated Questions

    Is it louder than Roush Axle Back?

    • This exhaust is not louder than the Roush Axle Back Exhaust. In terms of how loud both exhausts are, I would give the Flowmaster a 5/10 and the Roush a 8/10.

    Helpful (1)

    I currently have the Flowmaster scavenger resonator delete on my 2015 EcoBoost. This will fit right on to that right?

    • The Flowmaster American Thunder Axle Back Exhaust will mate with the Flowmaster Y-Pipe with no/minor modification required.

    Helpful (1)

    I thought that the Super 10's were one of Flowmaster's loudest products... But this says that it offers a moderate tone. Is it loud or moderate?

    • This system is rather loud. Volume is a bit subjective so we would recommend listening to some sound clips online. Most people find the American Thunder kit to be loud and aggressive.

    Helpful (1)

    I currently have the flowmaster outlaw on my 2016 v6 but would like to get this one instead. Would I just be able to install it without any further cutting?

    • The Flowmaster American Thunder Axle-Back Exhaust can be installed as a direct replacement for the Flowmaster Outlaw Axleback Exhaust.

    Helpful (1)

    Will this fit on my 2016 premium convertible?

    • The Flowmaster American Thunder Axle-Back Exhaust will fit the 2016 Premium Convertible Mustang not equipped with active exhaust.

    Helpful (0)
    Post Your Question
    1 More Question
    Hi, do you think it would be a good idea pairing American thunder axle-back with the X pipe? X pipe is really amazing when paired with Outlaws, but too loud. Never saw examples with American thunder. 1 answer

    Recommended For You

    Customer Reviews (6) Write a Review

    Overall Rating 4.8

    out of 5 stars

    Installation Time:Afternoon

    Installation Cost:0-$100

    • Loudness / Volume 4.333333 4.3
    • Exhaust Note 4.666667 4.7
    • Fit & Finish 5 5
    • Bang For Your Buck 4.833333 4.8

    • 5/5

      Installation Time: Less than 1 Hour

      February 22, 2018

      Review from Flowmaster American Thunder Axle-Back Exhaust (15-17 V6)

      Nice sound

      If your looking for a not overly loud sound but a nice deep sound this is it !! Love it no drone at highway speeds . Plus noticed throttle response


      Year: 2017 Submodel: V6

      Helpful (10)

    • 5/5

      Installation Time: Less than 1 Hour

      June 12, 2017

      Review from Flowmaster American Thunder Axle-Back Exhaust (15-17 V6)

      Well worth the price

      I was having a hard time choosing which axle back to get for my stang. Since most were pretty similar price wise, I went to YouTube to check some reviews and I fell in love with the sound. My biggest gripe with the v6 is that it's so quiet. This definitely solved that issue and I've loved every moment with it. It's loud, but not overtly obnoxious, and that is exactly what I wanted. The drone isn't too loud, I personally don't mind it. Other ones seem to have more of a drone/ricer sound, this one gave me the deep sound I was looking for. This was my first modification and I think I'm hooked now


      Year: 2015 Submodel: V6

      Helpful (13)

    • 4/5

      Installation Time: Shop Install

      Installation Cost: 0-$100

      May 08, 2017

      Convertible cab loud ...

      I ask my friends if they " want to hear what a real 4 cylinder sounds like ?" They laugh till I start it up and they are surprised it sounds pretty good . Its not an 8 cylinder sound by any means but it's not a rice burner sound either . I didn't want to be overly loud , like I thought the outlaw mufflers would be , because I have a convertible . These American Thunders are Convertible cab Loud . But not to to bad . I had to have something on it because I chose an unleashed Tune for my Turbo 4 and Flowmaster American Thunder axle-backs seemed the best way to let folks know it isn't exactly stock . I'm 62 years young so crawling around under the car is not my thing . I had them installed . Won't wake the neighbors but they will hear ya coming , just not from so far away . Great purchase in my book . If ya have a Vert just be prepared for the interior roar when you spur those ponies on .


      Year: 2015 Submodel: EcoBoost

      Helpful (10)

    • 5/5

      February 23, 2017

      Great Deep Sound

      These sound great and they are not obnoxious. Ford should have added performance exhaust as options. My old Fox body 5.0 was very loud and I loved it in my 20's. I wanted my ecoboost to have a nice exhaust note but not be heard 2 blocks away. They're Awesome and I'm very happy with them!


      Year: 2016 Submodel: EcoBoost

      Helpful (9)

    • 5/5

      November 20, 2016

      Review from Flowmaster American Thunder Axle-Back Exhaust (15-17 V6)

      Sounds awesome for v6!

      Wow. It's perfect. Loudness is great and the sound is so nice for a v6. Barely any drone too!


      Year: 2015 Submodel: V6

      Helpful (11)

    • 5/5

      September 18, 2016

      great sound

      the flow master american thunder axle-back exhaust it has good sound not noisy


      Year: 2015 Submodel: Ecoboost

      Helpful (8)

    Related Mustang Categories